Radio resources are national restricted intangible assets. As the number of users who use wireless devices rapidly increases, the value of radio resources is rapidly increasing. Specifically, the number of radio frequency (RF) services, for example, mobile communication, WLAN, digital broadcasting, satellite communication, radio frequency identification/ubiquitous sensor network (RFID/USN), Ultra Wide Band (UWB) communication, wireless broadband (WiBro), etc. is rapidly increasing, the demand for restricted radio resources is also rapidly increasing.
Cognitive Radio (CR) technology has been proposed by Joseph Mitola. The CR technology searches for and uses a frequency band that is allocated to a specific communication/broadcast service (or an enterpriser) and is not used in a specific region at a specific time, so as to increase frequency use efficiency.
TV broadcast band has been mostly focused as an operation band of a network based on CR technology (hereinafter referred to as a CR network). In recent times, Federal Communications Commission (FCC) has been announced the regulation of using the CR network for the TV broadcast band. Standardization of the CR network using the TV broadcast band is being intensively conducted by the international standardization organization such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11. Specifically, standardization of an IEEE 802.11-based CR network (hereinafter referred to as IEEE 802.11 TVWS network) is being intensively conducted by the IEEE 802.11af task group.